This specification relates to data processing.
The Internet provides access to a wide variety of resources. For example, video and/or audio files, as well as web pages for particular subjects or particular news articles are accessible over the Internet. Access to these resources presents opportunities for advertisements to be provided with the resources. For example, a web page can include advertisement slots in which advertisements can be presented. These advertisements slots can be defined in the web page or defined for presentation with a web page, for example, in a pop-up window.
When a web page (or another resource) is requested by a user, an advertisement request is generated and transmitted to an advertisement management system that selects advertisements for presentation in the advertisement slots. The advertisement management system selects advertisements, for example, based on characteristics of the web page with which the advertisements will be presented, demographic information about the user to whom the advertisements will be presented, and/or other information about the environment in which the advertisement will be presented.
Resource keywords that have been associated with a web page and/or advertisement keywords that have been associated with an advertisement can also be used by the advertisement management system to select advertisements for presentation in the advertisement slots. Resource keywords can be specified by a publisher of the web page and/or selected, for example, based on text that is contained in the resource. However, some resources may include little or no text from which keywords can be selected.